Multilayer substrate and probe card

Abstract

It is an object of the present invention to dramatically reduce thermal deformation without using any special material in a multilayer substrate and a probe card. According to the present invention, in a probe card including at least one circuit board connected in an electrically conductive manner to a probe brought into electrical contact with an inspection object, the circuit board includes a base layer and a surface layer stacked on at least an inspection object side surface of the base layer. The surface layer has a higher coefficient of thermal expansion than that of the base layer, and grooves dividing the surface layer into a plurality of areas are provided in the surface layer.

What is claimed is: 
     
       1. A multilayer substrate comprising: a base layer; and a first surface layer stacked on at least one surface of the base layer, the first surface layer having a higher coefficient of thermal expansion than a coefficient of thermal expansion of the base layer,
 wherein grooves dividing the first surface layer into a plurality of areas are provided in the first surface layer, 
 wherein a second surface layer is made provided on the other surface of said base layer, and 
 wherein the grooves of said first surface layer are formed so as to make an amount of expansion of said first surface layer become closer to an amount of expansion of said second surface layer when a temperature difference occurs between both surfaces of the multilayer substrate. 
 
     
     
       2. The multilayer substrate according to  claim 1 ,
 wherein said base layer is exposed from the grooves dividing said first surface layer. 
 
     
     
       3. The multilayer substrate according to  claim 1 ,
 wherein said first surface layer is made of an organic insulating material. 
 
     
     
       4. The multilayer substrate according to  claim 1 ,
 wherein said base layer is made of an inorganic insulating material. 
 
     
     
       5. The multilayer substrate according to  claim 1 ,
 wherein the second surface layer is made of a same material as a material of the first surface layer on the one surface. 
 
     
     
       6. A probe card comprising at least one circuit board connected in an electrically conductive manner to a probe brought into electrical contact with an inspection object,
 wherein said circuit board comprises: a base layer; and a first surface layer stacked on at least a surface on the inspection object side of the base layer and on which the probe is disposed, the first surface layer has a higher coefficient of thermal expansion than a coefficient of thermal expansion of the base layer, and grooves dividing the first surface layer into a plurality of areas are provided in the first surface layer 
 wherein a second surface layer is provided on the other surface of the base layer, and 
 wherein the grooves of said first surface layer are formed so as to make an amount of expansion of the first surface layer become closer to an amount of expansion of the second surface layer at the time of inspection. 
 
     
     
       7. The probe card according to  claim 6 ,
 wherein the base layer is exposed from the grooves dividing the first surface layer. 
 
     
     
       8. The probe card according to  claim 6 ,
 wherein the first surface layer is made of an organic insulating material. 
 
     
     
       9. The probe card according to  claim 6 ,
 wherein the base layer is made of an inorganic insulating material. 
 
     
     
       10. The probe card according to  claim 6 ,
 wherein the second surface layer is made of a same material as a material of the first surface layer on the one surface. 
 
     
     
       11. A probe card comprising a contactor brought into electrical contact with an inspection object, the contactor including a plurality of probes and a circuit board to which the probes are attached,
 wherein said circuit board comprises: a base layer; and a first surface layer stacked on at least a surface on the inspection object side of the base layer and on which the probe is disposed, the first surface layer has a higher coefficient of thermal expansion than a coefficient of thermal expansion of the base layer, and grooves dividing the first surface layer into a plurality of areas are provided in the first surface layer, 
 wherein a second surface layer is provided on the other surface of the base layer, and 
 wherein the grooves of the first surface layer are formed so as to make an amount of expansion of the first surface layer become closer to an amount of expansion of the second surface layer at the time of inspection. 
 
     
     
       12. The probe card according to  claim 11 , wherein the base layer is exposed from the grooves dividing the first surface layer. 
     
     
       13. The probe card according to  claim 11 , wherein the first surface layer is made of an organic insulating material. 
     
     
       14. The probe card according to  claim 11 , wherein the base layer is made of an inorganic insulating material. 
     
     
       15. The probe card according to  claim 11 ,
 wherein the second surface layer is made of a same material as a material of the first surface layer on the one surface.